The present invention relates to a method and an apparatus for adjusting the inclination of the label, in a labeling machine for conical or non-cylindrical containers.
Labeling machines are known in which a film constituting the labels, generally made of plastic material such as polypropylene or polyethylene, is wound on a reel from which it unwinds to reach a cutting station where the film is cut into segments, each of which substantially corresponds to a label, which segments are then taken up by an aspirating holed roller which feeds a gluing roller before the final application of the label onto the container.
In the case of containers in which the area of application of the label is not perfectly cylindrical but is, for instance, conical or deformed, the label tends to adhere to the container in such a way that the opposite short sides of the label are not perfectly superposed but give rise to a slight offset in height.
The aim of the present invention is to eliminate the aforesaid drawbacks, making available a method and an apparatus that allow to apply film labels also on non-cylindrical, and in particular conical, areas of containers.
A further aim is to obtain this in a particularly simple and economical manner and to allow to adjust the positioning of the labels even when the machine is in motion.
Said aims are fully achieved by the method and by the apparatus of the present invention, which are characterized by the content of the claims set out below.
In particular the method provides, upstream of the cutting station, for having the inclination of the direction of feeding of the film, relative to the substantially horizontal normal direction of feeding.
The apparatus comprises means shaped in such a way as to provide for an inclination of the direction of feeding of the label film to the cutting station.
Said means preferably comprise an element anchored to an end of the rotating shaft of a roller for feeding the label film to the cutting station. On said element is screwed a screw operated through a knob, and the rotation of the screw causes the translation of said element and hence the displacement of the rotating shaft of the roller that feeds the film to the cutting station.
The other end of the shaft of the roller that feeds the film to the cutting station is preferably anchored to a universal joint or to an articulated joint.